


Anatomy Lesson

by ZaffreFennec



Category: Undertale (Video Game)
Genre: But smut is coming, Doing dating things, F/M, Fluffy Smut, Humans and monsters work differently, No ecto-genitals, Other, Reader Implied to be Frisk, Sensitive bones, not smut yet
Language: English
Status: In-Progress
Published: 2018-01-19
Updated: 2018-01-19
Packaged: 2019-03-06 16:52:15
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,481
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13415532
Author URL: https://archiveofourown.org/users/ZaffreFennec/pseuds/ZaffreFennec
Summary: You and Papyrus have been datemates for a while now.  During one of your nights together, you're invited up to your boyfriend's room for some questions.  Things start getting 'frisky' from there.





	Anatomy Lesson

"WELL, HERE'S MY ROOM, HUMAN!” Papyrus exclaimed with a flourish of his arm, "FEEL FREE TO LOOK AROUND TO YOUR HEART'S CONTENT!”  
  
You step forward and survey your skele-boyfriend’s now familiar abode. "Hey. you got some new action figures?”  
  
"WOWIE, YOU NOTICED!!!” The adorable grin that split his face made you giggle; god, you loved this dork. As silly as he could be, his earnestness and enthusiasm never failed to remind you why you started dating him. It had come out of the blue, one day Papyrus had come shuffling up to you uncharacteristically bashful with a bouquet of roses, asking for a second chance. It had taken you a moment to realize that by 'second chance’ he was referring to making up for that date you had went on together back when you were just a kid. After having laughed to a coughing fit that he was worried you were holding that against him, he got an enthusiastic 'yes’ and a movie-date that Friday. You'd been steady ever since.  
  
This date was just as charming as ever, the two of you sharing a candlelit spaghetti dinner and curling up on the couch together to watch some cheesy action flick. You had noticed that Papyrus wasn't cheering as loudly at the one-liners as he usually did, and throughout the finale he seemed especially fidgety. In response to your probing if everything was okay, he had fumbled out an invitation up to his bedroom. Worried that he needed to tell you something important, you followed gingerly behind him as you both climbed the stairs to his door.  
  
"So," you said, pulling the chair out from his computer desk and sitting down in it, leaning forward with your fingers steeped, "what's on your mind?”  
  
Papyrus shifted from side to side, scratching the back of his skull. "W-WELL, UM, TH-THERE’S SOMETHING I WANTED TO TALK TO YOU ABOUT. IT'S...HMM, HOW DO I PUT THIS?” he said, tugging a new hole in his crimson scarf.  
  
You stared, trying to hold in a smirk. Was he going where you thought he was going? Was Papyrus, dorky, oblivious, exuberant Papyrus, YOUR Papyrus, trying to broach ‘relationship matters’? You waited with bated breath.  
  
“I THINK IT'D BE EASIER IF I SHOWED YOU,” he said as he turned and pulled a science book from beneath his pillow. An anatomy book, to be precise. Hoo boy. Thumbing through, he scanned the pages until he found what he was looking for, a slight blush coming to his cheeks. “HUMANS ARE REALLY INTERESTING, THEY'RE MY FAVORITE THINGS TO READ ABOUT NEXT TO PUZZLES, AND SINCE WE'VE RETURNED TO THE SURFACE, I'VE BEEN FINDING A WEALTH OF NEW RESOURCES TO PERUSE. A-AND SO I'VE FOUND...THIS.” He glanced back down at his textbook, cheekbones getting even redder. “HUMAN, WHAT I'M ABOUT TO ASK YOU ABOUT IS OF THE UTMOST IMPORTANCE.” With expression serious and posture urgent, he turned the book around to face you. “IS IT TRUE???”  
  
You burst out laughing. You couldn't help it, the absurdity of it all and Papyrus’ seriousness just became too much. “Yes, Papy,” you gasped as you collected yourself, “Humans do in fact have skeletons inside them.”  
  
“NO!!! COULD IT REALLY BE???” He shouted, book flung into the air with abandon. Flabbergasted would be a fitting description of his expression. “DO YOU KNOW WHAT THIS MEANS? MY THEORY ABOUT HUMANS DESCENDING FROM SKELETONS IS ONE STEP CLOSER TO BEING VALIDATED!” He swept you up into a huge bear hug, twirling you around. When you were finally set back down on your feet, you felt flushed with happiness, albeit slightly dizzy.  
  
You looked up to find Papyrus looking at you with an odd expression. Slowly, his hand skirted up your arm and over your shoulder to trace your collarbone, his fingers probing like it was the first time he realized it was there. You grasped his hand in yours, a gentle touch to bring him back to Earth. “HUMANS REALLY ARE INTERESTING,” he murmured. From the way he wasn't quite able to meet your eyes, you knew something was bothering him. His gloved thumb stroked the back of your palm nervously.  
“Would you like a closer look?”  
  
“REALLY? YOU'D BE OKAY WITH THAT?” Well when he was looking at you like you were a present on Christmas morning, how could you say no? Stepping back a bit, you lifted your shirt up and over your head, cute bra with a little pink ribbon in the front underneath.  
  
“Would you like to do the honors?” you asked, turning around to give him better access to your bra clasp. Feeling his sturdy, gloved hands brush your back, you shrugged the straps off your shoulders as he fumbled the hooks apart. In one fluid motion you took off both your pants and underwear, stepping out of them into the state you entered the world in. You pivoted around to face him again, a sudden wave of self-consciousness causing your cheeks to redden. “Tada! Um, I know I'm not in the best of shape, but--”  
  
Papyrus reached out suddenly, his big hands slipping under your arms to lift you high into the air like an unwrapped doll, “WOWIE!!! WHY DIDN'T YOU TELL ME YOU LOOKED SO GOOD NAKED? I WOULD HAVE ASKED TO SEE YOU LIKE THIS AGES AGO!!!”  
  
“Woah, hey! Easy, tiger,” you yelped, clinging to his forearms to chase away the feeling of falling. “I'm feeling just a little bit vulnerable right now, okay? Humans are kinda sensitive in this state.”  
  
Just as suddenly he scooped you into a bridal style embrace, arms sturdy as thick tree branches, his face full of worry. “I'M SORRY, HUMAN, I'LL BE MUCH MORE CAREFUL, I PROMISE.” Carrying you like a box of porcelain, he walked as delicately as his lanky frame would allow over to his bed, laying you down onto impeccably folded sheets, “I DIDN'T HURT YOU, DID I?”  
  
You reached up and cradled his cheekbone as he fretted above you, “Papy, it's okay, don't beat yourself up over this, I'm not hurt. Just don't get too rough exploring, okay?”  
  
“OKAY,” he said, smiling with relief. Clambering away, he returned to prop his anatomy book on the bed frame, flicking through to where he left off. He slipped his gloves off one at a time, gently probing for the skeleton beneath your skin with his phalanges. He started to explore first at your head, his feeling of your skull massaging your scalp, then your face, then your neck. You sighed contentedly; you could tell Papyrus was struggling to contain his excitement, enraptured by all your human body’s mysteries, taking utmost care not to press too hard or leave you with any bruises. His hands traveled lower. “AM I DOING ALRIGHT?” he asked, uncharacteristically soft-spoken. You nodded, the smile splitting his face only widening yours with it.  
  
Once again he traced your shoulders and clavicles, entranced by their curvature beneath your skin. “I REALLY NOTICED HOW SHAPELY YOU WERE,” he murmured, fingertips indenting your flesh as they traveled, just a little too much pressure to ghost, but not unpleasant. “HUMAN? I'D BEEN MEANING TO ASK YOU...” He cocked his head as his hands traced even lower, “UM, WHAT ARE THESE CALLED? ON YOUR RIBS?”  
  
“Those,” you say, squirming coyly from his poking, “are called boobs.”  
  
You watched wonder and awe cross his face as he kneaded your breasts, taking particular interest in your nipples as they stiffened from the attention they were getting. “WOWIE! THEY'RE SO SOFT AND SQUISHY!” As if to emphasize the statement, he poked your bust in glee as they jiggled, “SQUISH!”  
  
“Pfft, you're such a dork,” you laughed.  
  
“SQUISHSQUISHSQUISHSQUISH,” he teased. “YOU KNOW, I ALWAYS WONDERED WHAT IT FEELS LIKE TO HAVE SO MANY SQUISHY PARTS ON YOUR BODY. ESPECIALLY HERE,” he said, massaging your stomach, “IT'S SO DIFFERENT FROM WHAT SKELETONS HAVE…”  
  
“That's ‘cause humans have organs.” Papyrus cocked his head further. “Uh, like...your textbook probably has a section about that stuff, but for the most part you don't need extensive knowledge about it unless you're a doctor. Basically it's like a bunch of little flesh engines that process food and waste and just, like, handle the keeping-me-alive jobs of my body.”  
  
“FASCINATING! AND A LITTLE DISGUSTING, BUT MOSTLY FASCINATING!”  
  
“Admittedly, there’s a lil more squish there than there should be. I really should start dieting again…”  
  
“WHAT?! AND FORSAKE MY IMPECCABLE COOKING?! THERE MUST BE ANOTHER, LESS HARROWING, METHOD FOR YOU TO ACHIEVE YOUR IDEAL PHYSIQUE...OH! MAYBE YOU COULD COME TRAIN WITH ME AND UNDYNE!!!” You told him you'd think about it.  
  
His hands landed on your hips, and once again Papyrus fell unusually quiet. The way he cupped the crests of your pelvis and gently explored your underlying frame was almost reverent, and, though you might have imagined it, you swore you saw want in his eye sockets. “Such lovely hips,” he sighed, “So beautiful that they must be protected from the world by skin and organs and other human-y bits…” Wandering hands made their way toward your mound, rubbing at your ischium through your trimmed tangle of hair. You'd be lying if you said it wasn't getting you even a little excited, but at the same time you were content with the pace things were going.  
  
And then you really, REALLY weren't. As he gripped your hips, you squeaked in protest as Papyrus hoisted your lower half high up to meet his face, eye sockets burning holes into your privates as he stared with enraptured scrutiny. “HUMAN, WHAT IS THIS!?!?!?”  
  
“Put me down!” Just as quickly he lowered you back to the bed, hands withdrawing to knot fretfully at his chest. You curled into yourself, sitting up with your knees to your chest. “Hey, what'd I say about humans being vulnerable in this state!?”  
  
“I-I’M SORRY…” Goddamn Papyrus, stop looking so much like a kicked puppy. The anxiety that had made your heart leap into your throat ebbed as you unfurled.  
  
“It's okay, I'm not that mad, you just got a little carried away and I was caught waaay off guard.” Running your fingers through your hair in equal parts effort to calm yourself and pensive motion to think up a way to ease the tension, you felt the accumulating weight of every second of awkward silence between you two.  
“YOU CAN LOOK ME OVER TOO, HUMAN,” he said, unsure smile belying his embarrassment, “IF IT WOULD MAKE THINGS A LITTLE BETTER?”  
  
Actually, that wasn't a half bad idea. You wouldn't be the test subject anymore AND you both could still fool around together. It really would’ve been a shame to cut this so short. “C’mere, ya doofus, you're in the hot seat now.” You pulled his arm and he eagerly complied, switching positions with you. Lying on his back, he grinned as he struck a supine pose, earning a snort in laughter as response. Come to think of it, actually getting a chance to explore Papyrus’ body was still foreign territory. You knew he was a skeleton monster, obviously, but the 'monster’ half of the equation meant that he was just as much magic as you were meat, and that got the gears in your head turning. How much could he feel, especially without skin? Could a human anatomy book’s skeletal diagrams even be accurate for a being so evidently not human? This was going to be fun.  
  
Crawling beside him, you planted soft kisses on his forehead, gently trailing down to his cheekbones, mouth, jawline. Your tongue snaked out to trace his cervical vertebrae as your lips suckled gently. Papyrus’ ribcage rose and fell more rapidly as you heard the faintest moan slip past his teeth. You pulled his shirt over his head, not without a bit of help on his part, and let your eyes wander this new frontier. Twining your fingers along his chest, you probed the texture and shape of his ribs, careful not to push too hard and wedge your fingers between them.  
  
“OH STARS HUMAN, THAT'S NOT FAIR AT ALL! THIS IS SUPPOSED TO BE AN EDUCATIONAL ENDEA-EAH-AH!” Oh, so his spine seemed especially sensitive. That made sense. Grinning vixenly at your flustered test subject, you gave a few more experimental strokes. God he was cute when he was bashful; his hand covered his mouth in a failed attempt to stifle even a little bit his whimpers as his cheekbones flared under the stimulus, giving you a teasingly petulant glare. “TOTALLY UNFAIR.”  
  
“Mmm, something tells me you're not too keen on me stopping though, right?” you teased, kneading your hands more on his vertebrae, watching him squirm in a futile effort to remain composed, little pants and vocalizations serving as reward for your efforts. Creeping your massage upward, you made toward the void of his ribcage, curiosity driving you. A shift and sudden tenseness gave you pause as Papyrus seemed to stiffen defensively. “Not there?” you queried.  
  
“N-NOT YET, HUMAN. THAT'S A LITTLE TOO SENSITIVE THERE. UM, ALTHOUGH…” he trailed off, bashfulness washing over him once more, “C-COULD YOU GO JUST A LITTLE BIT, UM, L-LOWER…?” Reversing your trail, you again palmed at his spine, closer to his pelvic girdle. Leaning down, you lathed your tongue against him in a kiss against his lower vertebrae. Immediately you felt Papyrus’ hand entwine into your hair, gentle pressure holding you forward as he huffed.  
  
You were perfectly content to work your own kind of magic on Papyrus as long as you pleased, but a subtle flickering above your head caught your eye. In his rib cage floated a luminous heart, it's gentle light, reminiscent of the moon's pearly glow, pulsing akin to your own heartbeat. You felt that if you had the brazen gall to reach out and touch it, it would shatter like spun glass at your corporal presence. It was impossible to look away, only being able to whisper a few words as you remained transfixed. “It's so beautiful...Is that…”  
  
“OH! M-MY SOUL!” Papyrus crossed his arms around his chest, shoulders caved in as his cheekbones flared red. Looking back up at your now sitting form, he gave an apologetic laugh. “SORRY, I GUESS I'M A LITTLE SENSITIVE TOO...UM, THANK YOU FOR CALLING IT BEAUTIFUL, BY THE WAY…” Slowly his arms unfurled, drawn behind his head like he was putting himself on display, his unsure grin and searching eyes begging for approval, for acceptance. “SHOWING YOUR SOUL IS A REALLY PRIVATE THING FOR MONSTERS. I’M FEELING A LITTLE ON THE EXPOSED SIDE TOO NOW. BUT…” he paused, sucking air into his nonexistent lungs, “I’M GLAD IT'S YOU I’M SHOWING IT TO. IT FEELS EXTRA SPECIAL WITH YOU.”  
  
You took the opportunity to kiss his mouth, soft lips against rigid teeth. Despite the oddity of it all, it held all the intimacy you could have possibly wanted. His hand slipped into yours as their fingers entwined. Embracing each other like this, like datemates did, to finally take these next tentative steps closer to each other, felt so right; every difference and flaw was swept away. “HUMAN, I LOVE YOU,” Papyrus murmured, eyes hazy, “PLEASE, CAN I… WOULD YOU SHOW ME YOUR SOUL TOO?”  
  
Oh. Uh oh. You were sure Papyrus could see every gear in your head binding at his request as his own face mirrored your concern as you internally panicked. Show your soul? How? You would, readily so, but he might as well have asked you to fly for as unequipped as you were to meet his request. Guilt started to seep in; Papyrus had shown you HIS soul, it was obviously an important and intimate and special act, and here you were, sitting atop him and unable to reciprocate. Lost in your head, you shook yourself out of it to realize your boyfriend was trying to talk to you.  
  
“DID I GO TOO FAR??? I'M SORRY, I JUST, YOU WERE SO GREAT, HUMAN, AND YOU'RE SO SPECIAL TO ME, I JUST, I JUST THOUGHT…” You shushed him gently, heart twisting at his dismay. Oh please don't make that face, you fretted, gently stroking his cheek to keep him from tearing up.  
  
“Papyrus, I want to show you my soul too. I really do, it's just, I don't...” you floundered for the right words, the gentlest bomb drop, “I don't know how. Can you maybe show me, or...?”  
  
Beneath you, Papyrus went rigid and bug-eyed, struck by some unknown terror. If he had skin, you were sure all the blood had just drained from his face. Like a lamp burning out, his soul gave one lurching flare of light as it popped out of the ether as he scrambled out from under you, blankets dragged with him to be pulled up in front of his chest. All the while came an inconsolable stream of panicky apologies, hands white-knuckled and shaking. “I'M SORRY, I'M SO, SO SORRY, I DIDN'T REALIZE, OH GOD, OH NO, OH GOD--”  
  
“Shhh, Papy, it's okay, it's not--”  
  
“NO!!! NO, IT'S NOT OKAY!!! I'M SO SORRY, THIS IS ALL TERRIBLY WRONG, I--”  
  
“Stop!” you shouted, startling even yourself by your forcefulness. Thankfully it seemed to have broken through at least a few layers of panic, as Papyrus fell shiveringly silent, eyes looking everywhere but at you. At least you'd be able to talk now.  
  
And then he threw the blanket over your head.  
  
It was in one swift motion you found yourself needing to squirm your head out of your fabric entrapment, all the while being further cocooned by your increasingly distressed partner. Fighting his bony arms away and working to disentangle the rest of yourself, you scowled at him from your snuggly prison, “Pap, what the hell are you doing? Seriously, what WAS that reaction for? Like, I'm sorry I don't know soul magic or whatever, but I was gonna at least TRY to reciprocate, y'know? I gotta say, I'm not appreciating this.”  
  
He would not meet your eyes. Literally everything except you was Papyrus’ focus, and frankly it was starting to drive you up the wall. “HUMAN,” he croaked, “WE NEED TO STOP. RIGHT NOW. I KNOW WHAT WE WERE DOING MIGHT HAVE FELT GOOD, BUT IF I KNEW BEFORE THAT YOU WERE STILL, ST-STILL…” without a throat, somehow he still managed to swallow down bile, “STILL A CHILD, I WOULD HAVE NEVER, WE SHOULD HAVE NEVER, OH GOD WHAT HAVE I DONE…”  
  
You blinked. “Oh my God, what???”  
  
“ONLY MATURE MONSTERS, ONES THAT UNDERSTAND THAT SUMMONING THEIR SOUL MAKES YOU REALLY REALLY VULNERABLE AND IS HOW YOU MAKE BABY MONSTERS, CAN SUMMON IT. SOMETIMES INFANT MONSTERS CAN TOO, BUT IT'S ONLY BECAUSE THEY NEED TO DRAW OFF THEIR PARENT’S MAGIC TO SURVIVE. A-AND YOU CAN’T SUMMON YOURS, SO THAT HAS TO MEAN--”  
  
Oh. Oh… “Papyrus, baby, no,” you soothed, inching closer to stroke his cheek reassuringly. You couldn't help notice that for a split second he flinched at your touch. “Humans work so much differently from monsters, we literally don't DO soul stuff. I didn't even know humans COULD summon their souls until today, I thought it could only be drawn out like during a fight.” You pulled your skeleton into a hug, head resting on his shoulder. “I'm an adult, I promise. I mean, you were at my 18th birthday, do you even remember how long ago it was?”  
  
Papyrus pulled away to count on his fingers. And count again. And again. “I'M SORRY, I MUST BE TOO FRAZZLED TO EVEN THINK. IT WAS DEFINITELY A WHILE AGO, WASN'T IT?”  
  
“It’s been three years ago now. I’m an adult in just about everybody's book. I'm sorry, I wish I could have let you know about humans and souls and stuff you you didn't have to be scared like that.”  
  
Finally he began taking in deeper breaths, “IM SORRY TOO, HUMAN, I SHOULDN'T HAVE PANICKED SO QUICKLY. OH SHOOT, I'VE GONE AND RUINED THE WHOLE NIGHT…”  
  
“Don't beat yourself up about it,” you chided, sidling up against his rigid frame in the form of a cuddle, “Tonight was still a lot of fun, it always is when I'm spending time with you. And, uh, besides,” you chuckled darkly, “that was definitely the, um, 'correct’ response towards thinking you almost slept with a kid. Kudos there, I guess…”  
  
Papyrus sighed. “THIS HAS ALL BEEN TOO MUCH EXCITEMENT FOR ONE NIGHT. CAN WE MAYBE PUT ASIDE THE HUMAN ANATOMY EXPLORATION THINGIE FOR ANOTHER TIME?”  
  
“Mhmm,” you replied. With all that had gone on, only now did you realize how much energy you didn't have. “Let's get some shut eye for now, this can all wait for whenever.”. Pulling the both of you down, you detangled the wad of blankets into something that could more reasonably be slept under. “G’night Papy. Love you.”  
  
“I LOVE YOU TOO, MY HUMAN.”


End file.
